diff --git a/changelog.d/6734.bugfix b/changelog.d/6734.bugfix
new file mode 100644
index 000000000000..20eafabd448c
--- /dev/null
+++ b/changelog.d/6734.bugfix
@@ -0,0 +1 @@
+Warn if postgrse database has a non-C locale, as that can cause issues when upgrading locales (e.g. due to upgrading OS).